Rebekah Brooks has hit out at the decision to charge her with three counts of conspiracy to obstruct the course of justice, describing the case against her as "an expensive sideshow" and a "waste of public money".

Looking tired and nervous, the former News International chief executive chose to speak after her husband, Charlie, making a set of brief remarks in which she attacked the Crown Prosection Service's decision to bring charges on Tuesday morning.

Speaking live to camera outside the central London offices of her lawyers, Kingsley Napley, shortly before 5.30pm on Tuesday, Brooks said: "Whilst I have always respected the criminal justice system, I have to question today whether the decision was made on a proper impartial assessment of the evidence.

"I understand and know that there needs to be a proper and thorough investigation, and I am baffled by the decision to charge me. More importantly, however, I cannot express my anger enough that those closest to me have been dragged into this unfairly.

"One day the details of this case will emerge and people will see today as an expensive sideshow, and a waste of public money as a result of an injust and weak decision.

"I was the editor of the News of the World and the Sun, and chief executive. Even News International's harshest critics can't wish to see today, people with no involvement of the central issues being treated like this."

Standing shoulder to shoulder with her was her husband, who spoke first. Charlie Brooks will be charged with one count of conspiracy to pervert to course of justice.

"I feel today is an attempt to use me and others as scapegoats, the effect of will be to ratchet up the pressure on my wife, who I also believe is the subject of a witch-hunt," the racehorse trainer and Daily Telegraph columnist said, in a tone noticeably more strident than that used by his wife subsequently.

He continued: "There are 172 police officers, the equivalent of eight murder squads working on this; so it is no surprise me that the pressure is on to bring prosecutions, no matter how weak the cases will be.

"I have no doubt that the lack of evidence against me will be borne out in court, but I have grave reservations that my wife can ever get a fair trial, given the huge volume of biased commentary that she is constantly subjected to. We will fight this in court."

With both statements read out on live television the couple walked back into the lawyers' office. One reporter present shouted out: "Have you had a message of support from the prime minister?" but neither acknowledged the question as they headed back inside.

• This article was amended on 15 May 2012 to clarify the number of charges brought against Charlie Brooks by the CPS.